"I expect to sit down with them and my client early next week to draw up papers to submit to the European court," he was quoted as saying.
Praveen has said the two inquiries established into his wife's death did not satisfy him or her family.
The first was set up by the Health and Security Executive (HSE), while the second by the Health Information and Quality Authority (HIQA). Both will be held in private.
O'Donnell said the family had received offers of support from women's and human rights groups across the world in its quest for a public inquiry into Savita's death.
Savita died on October 28 at Galway University Hospital. She had been 17-week pregnant and was found to be miscarrying.
Praveen has said she asked repeatedly for a termination of the pregnancy but was refused on the grounds that the foetal heartbeat was still present and "this is a Catholic country".
The miscarriage lasted from October 21 to 24, according to Praveen. His wife contracted septicaemia and died on October 28.